A quality of service (Quality of Service, QoS for short) technology is a technology used by a network device to ensure quality of forwarded user data, and it mainly performs measurement by using metrics such as a bandwidth, delay, and packet loss rate. For an Internet Protocol (Internet Protocol, IP for short) network, because a packet is processed in a best-effort forwarding manner, some types of services (such as video and voice) may not be forwarded in a timely manner and consequently service quality cannot meet a requirement if no QoS mechanism is provided. Therefore, a QoS capability of a network device is a very important measurement standard. The network device mainly uses a queue and scheduling mechanism to support the QoS. A queue is a basic unit of scheduling and indicates a property or type (for example, a source port or destination port corresponding to a packet, a priority of the packet, and the like) of a current packet. The scheduling mechanism uses different algorithms (for example, a priority-based algorithm and a weight-based algorithm) to make a determination, so that the current packet in a queue is forwarded and processed.
To solve problems of excessive network nodes, complicated networking, and management difficulties, a network virtualization solution is introduced into the industry. A network virtualization device is formed by a central module and a remote module. A broadband remote access server (Broadband Remote Access Server, BRAS for short) or a service router (Service Router, SR for short) on a network is virtualized as a central module and is mainly responsible for control processing and service forwarding processing. An optical line terminal (Optical Line Terminal, OLT for short) on the network is virtualized as a remote module, and is mainly controlled by the central module, accesses user data through a remote port, and sends the user data to the central module for forwarding. A basic technology for network virtualization includes horizontal virtualization and vertical virtualization. In horizontal virtualization, two or more central modules are clustered as one device; a unified management plane is used to perform management; a unified control plane is used to process a routing protocol and establish a forwarding entry; and a received data packet is forwarded by locally searching a table. In vertical virtualization, a remote module and a central module are combined as two parts of a virtual device by using an internal interconnection channel; the remote module is managed and controlled by the central module; logically, the remote module and the central module are not two devices any longer; a data packet is sent, according to a local forwarding table of the remote module, to the central module for forwarding; and the internal interconnection channel is mainly implemented by establishing an internal pseudo wire (Pseudo wire, PW for short) based on IP and Multi-Protocol Label Switching (Multi-Protocol Label Switching, MPLS for short). At present, the QoS in the network virtualization solution cannot be implemented by using a perfect solution, and is still implemented by using a same method as that in a non-virtualization scenario. That is, the central module and the remote module separately perform QoS processing without cooperating well with each other. When forwarding traffic to the central module, the remote module does not consider an actual processing capability of the central module, resulting in frequent network congestion on the central module. For example, when a plurality of remote modules is connected to a physical interface of the central module by PWs, because bandwidth configuration for the PW of each remote module is separately performed, a sum of configured bandwidths of the PWs connected to the same physical interface of the central module is often greater than a bandwidth of the physical interface of the central module. When the sum of the configured bandwidths of the PWs connected to the same physical interface of the central module is greater than the bandwidth of the physical interface, a real-time bandwidth of the traffic sent by a plurality of remote modules to the central module through the PWs may be caused to exceed the bandwidth of the physical interface, resulting in problems of network congestion, packet losses, and the like.